The present invention relates to a sleeve for installation on a reel used to wind metal strip into coil form, and particularly to a compound sleeve for installation on an expandable and collapsible reel so as to prevent creases and other marks from occurring in the strip during winding of the coil thereon.
In the coiling of steel strip, the strip is commonly wound onto a segmented reel that can be expanded and contracted to permit alternate winding of the strip into coil form and removal of the wound coil therefrom. A problem is that creases often occur in the first few wraps of the coil especially at locations where the edge of the head end of the strip is subsequently covered by the next wraps. Creases also occur at locations where the segments are expanded since there is usually a slight gap or depression at the jointure of the segments. These gaps or depressions result in creases for several of the first wraps of the strip over the segments. Their occurrence is believed to be more prevalent when the reel becomes slightly out-of-round on expansion or slightly twisted during winding of the coil. The creases are more prominent on thinner gage strip and are especially undesirable on strip for automotive applications. Often several of the innermost wraps of the coil must be scrapped since creases are unacceptable to the customer.
It is known to use rubber or leather sleeves or boots on the segmented reel to prevent creases in the strip, however, these have been notably unsuccessful. A number of problems with the boots seemed unsolvable. The boots permitted slippage between the reel and the boot and the boot and the coil. To prevent slippage, holes were provided for bolts used to secure the boot to the reel. However, the holes left marks in the coil. Plugs were provided for the holes but tended to wear away and also result in marks subsequently. Keys were tried for attaching the boot to the reel but caused flat spots on the outer surface of the boot. Also, if the boot was soft enough to prevent head-end creases, it tended to become out-of-round upon expansion of the reel, and segment or filler bar creases still occurred at the gaps or depressions between the segments. Also, staggered coil edges sometimes resulted from the use of relatively soft, spongy boot material.
U.S. Pat. No. 3,008,663, Blackman, et al, discloses a tensioning drum D having a rubber face with oppositely inclined flexible projections formed by radially inward slits on each side of the transverse center of the drum. The use of an elastic sheet having tapered ends and placed between the inner wraps of a coil is disclosed in JA-No. 7319067. U.S. Pat. No. 3,592,406, Martin, et al, discloses a polyurethane elastomeric covering on a reel for storing steel cable. The polyurethane is 0.5 mils or more and preferably 8 to 15 mils thick and has a tensile strength of about 1600 psi. A brass facing on expandable segments of a mandrel for coiling strip is disclosed in U.S. Pat. No. 1,603,017, Biggart, et al. U.S. Pat. No. 2,726,051 discloses the use of conventional automotive brake linings on a conventional coiler reel. A plurality of metal sleeves designed to successively contract from the outer to the inner sleeve as radial pressure from winding of the coil increases are disclosed in U.S. Pat. No. 2,332,293. Finally, a core for adhesive tape is disclosed in U.S. Pat. No. 3,179,245, Bastian. The tube base may be of thermoplastic material. A collapsible synthetic resinous foam is provided over the base to permit relief of pressures built up within the roll during winding when the roll is subsequently heated to temperatures within the range of 35.degree. to 135.degree. C. A metal sleeve fixed to the mandrel of a coil winder is disclosed in J No. 86012976.